Chuck Bednarik (60) of the Eagles looks on after delivering a bone-jarring hit on Frank Gifford during game in 1960.

It was nearly 55 years ago exactly that Chuck Bednarik of the Eagles hit Frank Gifford so hard at Yankee Stadium one Sunday that he knocked Gifford out, knocked him out of that game eventually out of football for a year. He ended up in St. Elizabeth's Hospital with what was, at the time, as famous a concussion as there had ever been in the National Football League.

They have always called them concussions in pro football and talk now about concussion protocols because it has never been good for business calling them what they really are, which means brain wounds.

"It was clean," Gifford told his wife at the time, Maxine, in the hospital that day, because that was Frank Gifford, not wanting Bednarik to be blamed at the time for being even more brutal than normal in a brutal game because of the way he stood triumphantly over him when Gifford was lying on his back.

"At first we thought Frank was dead," Sam Huff would say, about a hit, and a moment, that would forever join Gifford and Bednarik in football history.

Of course Gifford, one of the great stars in Giants history and NFL history, one of the glamorous figures in the history of American sports, came back to play more Sundays — and take more hits — because he was a player and that is what players do. They go back in the game, sometimes before they are ready to do that, or before they should. The most vivid image of this NFL season isn't any catch or throw or run, it is Case Keenum, the Rams quarterback, staying in his team's game against the Ravens last Sunday despite suffering a concussion of his own, struggling to get to his feet and looking like a boxer who had taken too many shots to the head; who should have been tackled again before any coach or referee or spotter in the press box allowed him to keep playing football.

The hit on Frank Gifford was clean. So was the hit that put down Case Keenum, and snapped his head back on the turf. He got up and stayed in there. They never want to take themselves out of the game, even now, in the world of Chronic Traumatic Encephalopathy (CTE), and everything we know about what this sport does to the human brain, and everything the movie-going public will learn about CTE and the doctor, Bennet Omalu, who finally brought it into the light.

How the Daily News covered the story.

Now it comes to light that Frank Gifford was another suffering from CTE when he died. He lived a good, long life, everybody knows that about him. He was famous from the time he was a football star at the University of Southern California in the 1950s until he died at home in Greenwich, Conn. earlier this year at the age of 84. So he did not die young, or die by his own hand, the way others suffering from CTE have. He went from football to television and then even to a famous marriage to another television star, Kathie Lee Gifford.

But even Frank Gifford, whom Pat Summerall once described to me as the guy other guys wanted to be, took too many shots to the head while he was No. 16 of the Giants, starting with the one he took from Chuck Bednarik when it was Giants vs. Eagles in November of 1960. He retired and came back. He went back into the game. So did Case Keenum last Sunday, who managed to get through the rest of that game without taking another shot to his own head.

So you know, here is a definition of CTE:

"Chronic Traumatic Encephalopathy is a progressive degenerative disease of the brain found in athletes (and others) with a history of repetitive brain trauma, including symptomatic concussions as well as asymptomatic sub-concussive hits to the head."

Former middle linebacker of the Philadelphia Eagles Chuck Bednarik acknowledges the crowd during the game between the Detroit Lions and Philadelphia Eagles on September 23, 2007.

Sometimes it gets you when you are young. And sometimes it waits. And waits. People always say that nothing can kill the popularity of the NFL, that it will always be around, and as big as ever. They used to say the thing about another sport whose foundation was symptomatic concussions and "sub-concussive hits to the head: Boxing.

Mike Webster, the great old Steeler, was the first diagnosed with CTE by Dr. Omalu. He is the brilliant forensic neuropathologist — he will be played by Will Smith in the movie — who studied tissue from Webster's brain and other former NFL players, and found the kind of damage that he had only previously seen in people with dementia, including people who boxed for a living.

Hall of Famer Frank Gifford in his playing days.

Gifford died this year.

This is a piece of the statement released by the Gifford family on Wednesday:

"While Frank passed away from natural causes this past August at the age of 84, our suspicions that he was suffering from the debilitating effects of head trauma were confirmed when a team of pathologists recently diagnosed his condition as that of Chronic Traumatic Encephalopathy."

He lived a long, full life. He was Frank Gifford, after all, the guy other guys wanted to be when he was young. He did not end up living out of his car and in train stations the way Mike Webster did. He did not kill himself because of CTE the way Junior Seau and Dave Duerson did. But in the end all the shots to the head even caught up with Frank Gifford, caught him from behind when he was old instead of young. It probably began a long time ago, at Yankee Stadium, with the most famous shot of them all.